The present invention relates to a device for measuring the winding hardness of a strip, especially a strip of paper, that has been wound into a reel, the device consisting of a mechanism for extracting a slip that has been inserted tightly between two coils of the reel of paper with one end extending out of the side of the reel and of a dynamometer that measures the force necessary to extract the slip over a certain distance.
In a known measuring device of this type the winding hardness is determined graphically. The force necessary to extract the slip over a certain distance is plotted in a graph and the mean slope of the resulting curve is used as a measure of winding hardness.
Errors can occur as the result of the coefficient of friction of the material employed. A known way of avoiding these errors is to enclose the slip in an envelope before laying it between the coils. The envelope remains in the reel when the slip is extracted.